Table 2.

Effect of dietary Se yeast supplementation on the laying performance of Longyan laying ducks (n = 6)^a.

Items	Supplemented Se level from Se yeast, mg/kg				SEM	P-values
	0	0.05	0.15	0.25		Treatment	Linear	Quadratic	Cubic
Laying rate, %	59.2	55.8	54.6	58.8	2.40	0.466	0.973	0.120	0.893
Egg weight, g	56.6	56.7	57.1	57.1	0.49	0.841	0.409	0.787	0.832
Egg mass, g/day/bird	33.5	31.6	31.2	33.6	1.40	0.501	0.877	0.138	0.872
Feed: egg ratio	5.02	5.29	5.36	4.97	0.222	0.528	0.794	0.153	0.909

Se yeast, selenium-enriched yeast.

SEM, standard error of the mean.

^aMeans were calculated using six replicates per treatment (20 ducks per replicate).